jpg, where is exif data written?

[Aubrey]

I have scanned negatives to jpg and then added descriptions.
When I put this jpg through Image Batch Processor, to reduce the size, the description metadata is lost is the resulting file.
Within the Image Batch Processor I have set "Always write metadata to output file".
I have also ticked XMP:All Data.

Where is the description metadata stored in the the jpg (there is no buddy file created)? Is it only stored in the database? But if only stored in database the description should still be copied to the resulting file.

Aubrey.

[Mario]

JPEG files always have XMP data embedded in the file directly, never in sidecar files.
After the batch processor has created the file, it lets ExifTool copy the metadata over from the source file.

I just tried that with a JPEG file containing a XMP title, description, keywords and copyright info. Using the "Copy XMP::All Data" mode, the output file has all the XMP data of the original file. No EXIF data though, because this was not selected.

Please double-check your settings.